Re: Simple Real_Time.Time_Span question

[dennison@telepath.com]

In article <7003e4$534@hacgate2.hac.com>,
  "David C. Hoos, Sr." <david.c.hoos.sr@ada95.com> wrote:
>
> dennison@telepath.com wrote in message <6vvsgo$rvo$1@nnrp1.dejanews.com>...
> >I need to convert values of Ada.Real_Time.Time_Span into floating point
> >values for use in time-based simulation calculations. I'd think there *has*
> >to be a way to do this, but I don't see one. All I see is the ability to do
> >it indirectly via a conversion to Duration. But that looses the extra
> >accuracy of Time_Span, which was the whole point of using it in the first
> >place.
> >
> >Am I missing something?
>
> Yes, a couple of things, anyway, viz.:
>
>     1.  I think you're talking about precision and not accuracy.
Ok. Fine. "precision".

>     2.  Since the types involved are defined in the RM as
> implementation-dependent, it is implementation-dependent whether there is
> any loss of precision going from Ada.Real_Time.Time_Span to Duration.  In

I didn't miss that at all. That *was my point*. Consider the following:  o 
My vendor didn't bother to document the definition of Duration.  o  This code
is very likely to be ported to other RTOS/Compiler combinations.  o  A
typical real time simulation needs to perform floating-point caculations
based on the elapsed time since the last calculation. I know telemetry
applications also need this. Probably many (most?) other real-time
application domains need this as well.

  Thus a package billed as "Real_Time" ought to provide a portable way to get
a floating point value of a delta time (time_span). Where is it?

--
T.E.D.

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